Definition of Syndrome, Zellweger

Syndrome, Zellweger: A genetic disorder, also called the cerebrohepatorenal syndrome, characterized by the reduction or absence of peroxisomes (cell structures that rid the body of toxic substances) in the cells of the liver, kidneys, and brain. Zellweger syndrome is one of a group of disorders called the leukodystrophies, all of which affect the myelin sheath, the fatty covering which acts as an insulator on nerve fibers in the brain.

The most common features of Zellweger syndrome include an enlarged liver, high levels of iron and copper in the blood, and vision disturbances. Some affected infants may show prenatal growth failure. Symptoms at birth may include lack of muscle tone and an inability to move. Other symptoms may include unusual facial characteristics, mental retardation, seizures, and an inability to suck and/or swallow. Jaundice and gastrointestinal bleeding may also occur.

There is no cure for Zellweger syndrome and there is no standard course of treatment. Infections are guarded against to prevent such complications as pneumonia and respiratory distress. Other treatment is symptomatic and supportive.

The prognosis (outlook) with Zellweger syndrome is poor. Death usually occurs within 6 months after onset, and may be caused by respiratory distress, gastrointestinal bleeding, or liver failure.

The syndrome is caused by mutations (changes) in any of several different genes involved in peroxisome formation. These genes lie on at least two different chromosome locations including chromosome 2 (region 2p15) and chromosome 7 (region 7q21-q22).

The syndrome is named for the Swiss-born pediatrician Hans Zellweger (1909-1990) who came to the US and for many years was at the University of Iowa.